Step 1: Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper.
Step 2: In a large mixing bowl, combine the dry ingredients: sugar, cocoa powder, salt, baking powder, baking soda, and flour. Whisk until well combined.
Step 3: In a separate bowl, add the wet ingredients: vegetable oil, eggs, hot water, buttermilk, and vanilla extract. Whisk until smooth.
Step 4: Gradually add the wet ingredients to the dry ingredients. Mix until just combined.
Step 5: Divide the batter evenly between the prepared cake pans. Bake for 30-35 minutes, or until a toothpick comes out clean.
Step 6: Let the cakes cool in the pans for 10 minutes, then transfer them to a cooling rack to cool completely.
Step 7: For the frosting, combine powdered sugar, melted butter, vanilla extract, salt, and milk in a mixing bowl. Beat until smooth and creamy.
Step 8: Once the cakes are cooled, place one layer on a serving plate, frost the top, place the second layer, and frost the top and sides.
